Mounting for drill rig mast

ABSTRACT

A blast hole drill rig has a main frame turnably mounted on a mobile undercarriage and includes a mast support member mounted on the frame for limited pivotal movement about a horizontal axis. A horizontally displaceable boom formed as a massive beam is slidably supported on the support member and is reversibly displaceable with respect to the support member by a hydraulic piston and cylinder type actuator. An elongated mast is mounted on a support bracket which in turn is pivotally connected to one end of the boom and is pivotable by a pair of side-by-side hydraulic cylinder actuators interconnecting the boom and the support bracket.

United States Patent [191 Council [451 July 29, 1975 1 MOUNTING FORDRILL RIG MAST [75] Inventor: Malcolm N. Council, Richardson,

Tex.

[22] Filed: Dec. 26, 1973 [21] Appl. No.: 427,610

Primary ExaminerErnest R. Purser Assistant ExaminerWilliam F. Pate, I11Attorney, Agent, or FirmM. E. Martin [57] ABSTRACT A blast hole drillrig has a main frame turnably mounted on a mobile undercarriage andincludes a mast support member mounted on the frame for limited pivotalmovement about a horizontal axis. A horizontally displaceable boomformed as a massive beam is slidably supported on the support member andis reversibly displaceable with respect to the support member by ahydraulic piston and cylinder type actuator. An elongated mast ismounted on a support bracket which in turn is pivotally connected to oneend of the boom and is pivotable by a pair of side-by-side hydrauliccylinder actuators interconnecting the boom and the support bracket.

4 Claims, 8 Drawing Figures PATENTEI] JUL29 I975 SHEET PATENTEI] JUL 2 9I975 SET MOUNTING FOR DRILL RIG MAST BACKGROUND oF THE INVENTION Heavydrill rigs for drilling blast holes for quarries, surface mines, andother excavation work must be adaptable for drilling holes at variousangles with respect to the ground surface upon which the rig is located.Furthermore. in many work applications of heavy drill rigs it isnecessary to drill holes near a precipice or steep bank. Therefore.versatile positioning of the rig mast is desirable to provide fordrilling holes in the required locations and direction.

In heavy drill rigs of the rotary type substantial thrust forces must beexerted on the drill stem which forces are usually obtained by utilizingat least part of the weight of the rig itself. These thrust loadrequirements pose special problems in the design of the mast supportstructure particularly when as mentioned herein it is also required thatthe mast be mounted for versatile movement with respect to the mainframe of the rig. The present invention is directed to the solution ofthese problems in the art of heavy blast hole drill rigs and provides animproved mounting arrangement for a drill rig mast or rotary headsupport for a mobile blast hole drill. Mounting arrangements of varioustypes for percussion type drill rigs are disclosed in U.S. Pats. Nos.3,682.253 and 3,746,104 to l. A. Mclntosh et al. and in U.S. Pat. No.3,729,056 to F. W. Paurat. However, the mounting arrangements disclosedin these patents are not suitable for rotary type drill rigs or rigs inwhich substantial thrust forces must be transmitted from the main frameto the rig mast.

SUMMARY OF THE INVENTION The present invention provides for an improvedmounting arrangement for the rotary head support structure or mast of aheavy blast hole drill rig wherein the mast itself is positionable withrespect to the main frame of the drill rig for drilling holes in a widerange of directions with respect to said main frame.

In accordance with the mounting arrangement of the present invention anelongated mast structure is pivotally connected to the distal end of ahorizontally displaceable boom and is positionable with respect to theboom by a pair of side-by-side pressure fluid cylinder type actuators.The boom itself is mounted for limited movement about a horizontal pivotaxis and is formed as a massive beam whereby suitable support of themast with respect to the main frame of the rig is assured and heavydownthrust forces may be exerted on the drill stem by utilizing at leastpart of the weight of the drill rig itself.

Further in accordance with the present invention there is provided aheavy blast hole drill rig which is particularly adapted for drillingblast holes in a wide range of directions from a specific location ofthe drill rig itself without movement thereof thanks to the mountingarrangement of the drill rig mast.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sideelevation of a heavy blast hole drill rig in accordance with the presentinvention;

FIG. 2 is a longitudinal side elevation of the mast mounting arrangementof the drill rig of FIG. 1 taken from the opposite longitudinal side;

FIG. 3 is a section taken along the line 3-3 of FIG.

FIG. 4 is a section taken along the line 4-4 of FIG.

FIG. 5 is a section taken along the line 55 of FIG. 2;

FIG. 6 is a section taken along the line 66 of FIG.

FIG. 7 is a section taken along the line 77 of FIG. 2; and,

FIG. 8 is an isometric view of the pivotal connection between the boomand the mast positioner bracket.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 the mastmounting arrangement of the present invention is illustrated incombination with a mobile self-propelled blast hole drill rig generallydesignated by the numeral l0. The drill rig 10 is characterized by acrawler type undercarriage 12 upon which is disposed a main frame 14suitably mounted on a turntable 16 for turning movement with respect tothe undercarriage 12. The drill rig 10 also includes a suitable primemover such as an internal combustion engine mounted on the main frame 14and disposed within a shroud 18. An operators enclosure 20 is furtherprovided on the frame 14. The drill rig 10 may be of the so-calledrotary type in which a rotary head 22 is disposed for longitudinalmovement along an elongated mast 24. The rotary head 22 is connected toa pair of elongated flexible chains 25. The chains 25 are trained aroundsuitable sprockets disposed at opposite ends of the mast 24 in aconventional manner. A motor 27 is drivably connected to the chains 25for causing pulldown and hoisting movements of the rotary head 22. Therotary head 22 comprises rotary motor means for rotating a drill stem 26having a bit portion 28 attached to one end. A ground engaging member 30is pivotally connected to the lower end of the mast 24 for aiding instabilizing the rig 10 when the mast is in a working position.

The mast 24 is mounted on the drill rig 10 for movement between asubstantially horizontal transport position as shown in FIGS. 1 and 2 tovarious working positions, including those indicated by the dashed linesof FIG. 1, by means of an improved mounting arrangement disclosedherein. Referring to FIGS. 2 and 7 the mast 24 includes a pair of spacedapart parallel flanges 32 which are slidably disposed in channels 34formed on a mast positioner bracket 36. The mast may be supported withrespect to the bracket 36 in various longitudinally displaced positionsby means of an extensible hydraulic cylinder and piston actuator 38having one end 40 connected to the bracket 36 and the opposite andpiston rod end 42 connected to the mast.

Referring to FIGS. 5 and 8 also, the positioner bracket 36 is disposedon an elongated boom, generally designated by the numeral 44, which isdisposed on the drill rig 10 and is linearly movable with respect to themain frame 14. The boom 44 comprises a pair of sideby-side rectangulartubular beam members 46 upon which the positioner bracket is pivotallymounted. As shown in FIG. 5 the members 46 include bearing supports 48which journal pivot pins 50. The positioner bracket 36 comprises a pairof yokelike members 52 fixed to a transverse plate 53. Each member 52 ispivotally connected to a member 46 of the boom 44 by a pin 50. Thepositioner bracket 36 is pivotally displaced on the distal end of theboom 44 by suitable mechanism including two links 54 respectivelyconnected at their opposite ends to the yoke members 52 by pivot pins56; and to the piston rods 57 of a pair of extensible hydraulic cylinderactuators 58. Additionally, two pairs of link elements 60 are pivotallyconnected to the members 46 by pins 62. The ends of the link elements 60opposite the end connected to the boom 44 are pivotally connected to thelinks 54 intermediate the ends thereof. The positioning mechanismcomprising the bracket 36 and the links 54 and 60 provide for pivotalmovement of the mast 24 with respect to the boom 44 through asubstantial arc.

As shown in FIGS. 2 through 4 the boom 44 is supported on the main frame14 for limited pivotal movement about a horizontal axis substantiallyparallel to the direction of longitudinal movement of the boom withrespect to the frame. This pivotal movement of the boom 44 is providedfor by a boom support which includes a cradle member 66 formed in partby a pair of upstanding legs 68 and 70. The legs 68 and 70 arerespectively pivotally mounted on the main frame 14 by a pair ofbrackets 72 and 74 attached to the frame. The legs 68 and 70 are joinedtogether by two spaced apart longitudinal webs 76. The pivot axis of thecradle member 66 is perpendicular to the pivot axis of the mast 24 withrespect to the boom 44 which axis is formed by the pins 50.

The boom support is further characterized by a member 78 which isremovably fastened to the cradle member 66. The member 78 includes apair of spaced apart yokes 80 and 82 which are interconnected by atubular beam 84 formed by a pair of inwardly facing channel members. Asshown in FIG. 3 the member 78 is disposed between and connected to apair of generally upstanding hydraulic cylinder actuators 86 which aremounted on the frame 14 and are operable to be suitably extended andretracted for moving the boom support about the pivot axis formed by thebrackets 72 and 74 to position the boom 44 and the mast 24 in accordancewith a desired directional attitude for a drill hole. The members 66 and78 comprising the boom support are provided with a plurality of bearingblocks 88 and 90 which are disposed on the members for slidablysupporting the boom 44. The bearing blocks 88 and 90 are formed of asuitable low friction material desirably having self-lubricatingproperties. A preferred material for the bearing blocks 88 and 90comprises a nylon and molybdenum disulphide composition manufacturedunder the US. Trademark Nylatron. As shown in FIGS. 3 and 4 the bearingblocks 88 and 90 are disposed on the yokes 80 and 82 and on the legs 68and 70 of the cradle member 66 thereby being suitably spaced apart toprovide adequate support for the boom 44.

The tubular beam members 46 of the boom 44 are interconnected bysuitable structure including two webs 92 to form a massive beam forsupporting the mast. The boom 44 is horizontally movable on the supportby an extensible hydraulic cylinder actuator 96. The cylinder 96 isdisposed within the tubular beam 84 and is connected to the beam at oneend, as shown in FIG. 6. The connection of the cylinder 96 to the beam84 is formed by a spherical bearing 98 mounted on a bracket 100 which isfixed to the end of the cylinder 96. The piston rod 102 of the cylinder96 has an enlarged end portion which is connected to a bracket 103mounted on the boom 44, as shown in FIGS. 1 and 2.

The hydraulic cylinders 58 are connected to the boom 44 by dependingbrackets characterized as clevises 104 fixed to the tubular beams 46between the upstanding legs 68 and of the boom support. The cylinders 58are thus movable with the boom 44 when it is displaced with respect tothe frame 14. The cylinders 58 are actuated in unison to change theposition of the mast with respect to the boom 44 by pivoting the mastabout the axis formed by the pins 50.

With the mounting arrangement of the present invention the mast 24 maybe positioned in a wide variety of directional attitudes of the drillstem 26 without movement of the undercarriage 12. With the provision ofthe boom 44, which is horizontally slidable on the boom support, and thepivot mounting of the mast on the boom the mast may be moved away fromthe undercarriage a distance suitable enough to provide for drillingunder the drill rig itself. Moreover, the structural features of boom 44and its support are particularly adapted to adequately support the mastin any position attainable with the positioning mechanism disclosedherein and to transfer heavy pulldown forces to the drill stern byutilizing at least part of the weight of the undercarriage and mainframe plus the components mounted thereon. Thanks to the arrangement ofthe boom support and the cylinders 86 for pivoting the support about asubstantially horizontal axis the directional attitude of the mast anddrill stem may be further altered to com pensate for the terrain uponwhich the drill rig is parked or to be in accordance with the desiredattitude of a drill hole. Because of the heaviness of the rig 10including the mast 24 and attendant devices mounted thereon pivotalmovement about an axis which is perpendicular to the pivot axis formedby the pins 50 is preferably provided by the pivotal mounting of theboom support and the cylinders 86 rather than providing a pivotalmounting arrangement on the positioner bracket itself.

What is claimed is:

1. In a mobile drill rig including an undercarriage, a frame mounted onsaid undercarriage, and an elongated mast including a drill motormounted for movement along said mast for driving a drill stem, animproved mounting for said mast comprising:

a support mounted on said frame and comprising a cradle member includinga pair of spaced apart legs pivotally connected to said frame forlimited movement about a horizontal pivot axis formed by said pivotalconnection, said support being disposed between a pair of extensiblehydraulic cylinders connected to said frame and said support forpositioning said support about said horizontal pivot axis;

an elongated boom mounted on said support for linear movementsubstantially parallel to said horizontal pivot axis; and,

a positioner bracket pivotally mounted on one end of said boom andconnected to said mast whereby said mast may be pivoted with respect tosaid boom.

2. The invention set forth in claim 1 wherein:

said support includes a member removably fastened to said cradle memberand said support includes bearing means disposed on said member and saidcradle member for slidably supporting said boom.

3. The invention set forth in claim 2 wherein:

said bearing means comprises a plurality of bearing blocks disposed onsaid member and said cradle 6 member, said bearing blocks beingself-lubricating. mounted on said support for linear movement sub- 4. lna mobile drill rig includingan undercarriage, a stantially parallel tosaid horizontal pivot axis; frame mounted on said undercarriage, and anelona positioner bracket pivotally mounted on one end of gated mastincluding a drill motor mounted for movesaid boom and connected to saidmast whereby ment along said mast for driving a drill stem. an im- 5said mast may be pivoted with respect to said proved mounting for saidmast comprising: boom; and,

a support mounted on said frame for limited movea pair of extensiblehydraulic cylinders mounted side ment about a horizontal pivot axis; byside. each cylinder being connected to one of an elongated boomcomprising a pair of side-by-side said tubular members and to saidpositioner elongated tubular members fixed together by webs 10 bracket.interposed between said tubular members. and

1. In a mobile drill rig including an undercarriage, a frame mounted onsaid undercarriage, and an elongated mast including a drill motormounted for movement along said mast for driving a drill stem, animproved mounting for said mast comprising: a support mounted on saidframe and comprising a cradle member including a pair of spaced apartlegs pivotally connected to said frame for limited movement about ahorizontal pivot axis formed by said pivotal connection, said supportbeing disposed between a pair of extensible hydraulic cylindersconnected to said frame and said support for positioning said supportabout said horizontal pivot axis; an elongated boom mounted on saidsupport for linear movement substantially parallel to said horizontalpivot axis; and, a positioner bracket pivotally mounted on one end ofsaid boom and connected to said mast whereby said mast may be pivotedwith respect to said boom.
 2. The invention set forth in claim 1wherein: said support includes a member removably fastened to saidcradle member and said support includes bearing means disposed on saidmember and said cradle member for slidably supporting said boom.
 3. Theinvention set forth in claim 2 wherein: said bearing means comprises aplurality of bearing blocks disposed on said member and said cradlemember, said bearing blocks being self-lubricating.
 4. In a mobile drillrig including an undercarriage, a frame mounted on said undercarriage,and an elongated mast including a drill motor mounted for movement alongsaid mast for driving a drill stem, an improved mounting for said mastcomprising: a support mounted on said frame for limited movement about ahorizontal pivot axis; an elongated boom comprising a pair ofside-by-side elongated tubular members fixed together by webs interposedbetween said tubular members, and mounted on said support for linearmovement substantially parallel to said horizontal pivot axis; apositioner bracket pivotally mounted on one end of said boom andconnected to said mast whereby said mast may be pivoted with respect tosaid boom; and, a pair of extensible hydraulic cylinders mounted side byside, each cylinder being connected to one of said tubular members andto said positioner bracket.